First trimester spontaneous abortions occur in 15 to 20% of all clinically recognized pregnancies. Chromosomal -anomalies are responsible for more than 50% of spontaneous abortions. The majority (90%) of these chromosomal anomalies are numerical, particularly autosomal trisomies (involving chromosomes 13,16, 18, 21, 22), polyploidy and monosomy X. At birth chromosomal anomalies are still an imp...

BACKGROUND Triploidy may arise from fertilization of a mature haploid egg by two haploid sperm or by failure of meiotic divisions yielding a diploid gamete. We encountered a couple with habitual abortion, in which the last two fetuses were documented as viable triploid. METHODS To avoid dispermic penetration and development of abnormal preembryos, insemination was done by intracytoplasmic spe...

OBJECTIVE To estimate the proportion of other chromosomal abnormalities that could be missed if combined testing was replaced by cell-free (cf) DNA testing as the method of screening for trisomies 21, 18 and 13. METHODS The prevalence of trisomies 21, 18 or 13, sex chromosome aneuploidies, triploidy and other chromosomal abnormalities was examined in pregnancies undergoing first-trimester com...

With the advent of IVF technology, the terms normal and abnormal oocytes have been defined and one type of abnormal oocyte is the “giant oocyte”. Giant oocytes are defined to have a 30% larger diameter and twice the volume of normal oocytes[1,2]. Giant oocyte is a rarery observed phenomenon among humans and embryos may develop from these oocytes [2,3].The first hypothesis for the mechanism of t...

Chromosomal abnormalities are increasingly used to risk stratify adults with acute lymphoblastic leukemia. Published data describing the age-specific incidence of chromosomal abnormalities and their prognostic relevance are largely derived from clinical trials. Trials frequently have age restrictions and low recruitment rates. Thus we investigated these factors in a population-based cohort of 3...

A high incidence of haploid/diploid chimerism in chick embryos from strains of chickens selected for large size was postulated to be caused by the propensity of such hens to ovulate erratically. To test the hypothesis karyological analysis was made of embryos in eggs containing 1 or greater than 1 yolk. The eggs were from a line selected for multiple ovulation for 20 generations. Double and mul...